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Differential adaptation of the linear and nonlinear components of the horizontal vestibuloocular reflex in squirrel monkeysPrevious work in squirrel monkeys has demonstrated the presence of linear and nonlinear components to the horizontal vestibuloocular reflex (VOR) evoked by high-acceleration rotations. The nonlinear component is seen as a rise in gain with increasing velocity of rotation at frequencies more than 2 Hz (a velocity-dependent gain enhancement). We have shown that there are greater changes in the nonlinear than linear component of the response after spectacle-induced adaptation. The present study was conducted to determine if the two components of the response share a common adaptive process. The gain of the VOR, in the dark, to sinusoidal stimuli at 4 Hz (peak velocities: 20-150 degrees /s) and 10 Hz (peak velocities: 20 and 100 degrees /s) was measured pre- and postadaptation. Adaptation was induced over 4 h with x0.45 minimizing spectacles. Sum-of-sines stimuli were used to induce adaptation, and the parameters of the stimuli were adjusted to invoke only the linear or both linear and nonlinear components of the response. Preadaptation, there was a velocity-dependent gain enhancement at 4 and 10 Hz. In postadaptation with the paradigms that only recruited the linear component, there was a decrease in gain and a persistent velocity-dependent gain enhancement (indicating adaptation of only the linear component). After adaptation with the paradigm designed to recruit both the linear and nonlinear components, there was a decrease in gain and no velocity-dependent gain enhancement (indicating adaptation of both components). There were comparable changes in the response to steps of acceleration. We interpret these results to indicate that separate processes drive the adaptation of the linear and nonlinear components of the response.
Document ID
20040087955
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Clendaniel, Richard A.
(The Johns Hopkins University School of Medicine Baltimore, Maryland 21287-0910, United States)
Lasker, David M.
Minor, Lloyd B.
Shelhamer, M. J.
Date Acquired
August 21, 2013
Publication Date
December 1, 2002
Publication Information
Publication: Journal of neurophysiology
Volume: 88
Issue: 6
ISSN: 0022-3077
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: K08 DC-00150
CONTRACT_GRANT: R01 DC-02390
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Neuroscience

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